The present invention relates to an apparatus for recording and reproducing audio visual (AV) data.
Recently, a recording/reproducing apparatus using a hard disk drive (HDD) to store audio visual (AV) data is developed. This recording/reproducing apparatus enables implementation of various recording/reproducing modes by utilizing the large storage capacity and fast access of the HDD.
Japanese Laid-Open Publication No. 2000-187939 describes an example of an AV-data recording/reproducing apparatus using a HDD. This apparatus is connected to an external equipment via an IEEE1394 bus, and receives an AV stream and various control commands through the bus.
In view of the ease of extension of the functions and modification of the specification, it is effective for a microcomputer to control the overall operation of the AV data recording/reproducing apparatus. In other words, it is effective to employ a program control system. Moreover, there is a requirement for the AV data recording/reproducing apparatus as an AV equipment to quickly become accessible by the user after power-on (i.e., short starting time). This requires consideration of the storage location of the programs to be executed by the microcomputer.
For reduced starting time, it is convenient to store all programs in a rewritable, non-volatile memory such as a flash memory. However, this type of semiconductor memory has a great limitation on storage capacity, and therefore cannot store a large-size program. For example, a flash memory which is mounted on a microcomputer chip has a capacity of about 256 kilobytes. The use of a non-rewritable, non-volatile memory such as a mask ROM (Read Only Memory) would improve integration, but is not advantageous in terms of extension of the functions and modification of the specification.
For example, a 30 G-byte HDD for storing AV data may have a program storage region for storing all programs, so that the programs may be read onto a main memory, e.g., DRAM (Dynamic Random Access Memory) as necessary for execution. As opposed to the case of a general-purpose personal computer, however, this is not practical in the AV data recording/reproducing apparatus due to the long starting time of the HDD (the time required for the HDD to become accessible after power-on).